This application relates to an improved pallet for use with an over and under conveyor, wherein there is structure on the pallet and conveyor to positively drive the pallet between upper and lower runs.
Conveyors are known wherein a pallet moves frictionally along a pair of spaced endless members. The pallet runs along an upper run, where it typically carries a part, from one end of a conveyor path to the other. At the end of the conveyor path the pallet is turned from the upper run to a lower run where it is returned to its origination point. At the end of the lower run, the pallet is again turned back up to the upper run. In such systems the pallets typically move with the endless member through frictional contact. The pallets typically rest on the endless members on both the upper and lower runs, and move with the endless members, which are driven. In the prior art there has been some difficulties, however, turning the pallets between the upper and lower runs.
In one prior art system the pallet has chamfered surfaces at each end of a lower run support surface. These chamfered surfaces are intended to provide contact between the endless members and the pallet while the pallet is being turned between the upper and lower runs. Such systems do not have any actual positive engagement between the pallet and the endless member, however, instead they rely upon frictional contact. As the chain loosens, or as the pallet begins to wear, the adequacy of this frictional contact decreases. Thus, with such prior art systems, pallets may sometimes not turn properly between the upper and lower runs. This is undesirable.